I ran across this great article with tips on spotting credit card skimmers. Check it out for some pretty good info.

Ever wondered about the prices that criminals pay for skimmers? We recently studied this and found that the average price for magnetic stripe skimmers was between $100 – $300 US. Kits that include cameras and other techniques for also capturing PIN data (ATM & Chip/PIN transactions) were around 10x that amount on the black market. Home grown solutions are significantly cheaper to build, but often lack the subtlety and camouflage of the more “commercial” offerings.

By the way, note that even where Chip and PIN transactions have become the norm (outside the US), capturing the magnetic track data is still useful for attackers to focus on e-commerce and other card holder not present transactions.

Just a few things to think about… While the credit card theft underground is robust, interesting and dynamic, companies and issuers are working hard to stay on top of things. Unfortunately, the economics involved is complex, and attackers are continually refining all phases of their operations.